Synthesis and complexing properties of diglycol resorcinarene podands

Synthesis of new podands from resorcinarene and diethylene glycols are reported. The binding properties of these podands with alkali metal cations was studied by means of ESI–MS. The experimental results for podands with long diethylene glycol arms show the stable inclusion complexes with one or two metal cations and high affinity for sodium and potassium ions. This podands under appropriate conditions can thus form a sufficiently long cavity to accommodate more than one metal ion inside without disturbance of the axial symmetry like an ion channel. Podand with shorter arms, obtained from ethylene glycol form complexes with 1:1 stoichiometry and also readily dimers or trimers. In the presence of alkali metal cations this podand selectively binds cesium ions. The significant affinity of synthesized podands for the biologically important alkali metal ions may affect living organisms. Antibacterial activities were tested with series of Gram-positive and Gram-negative bacteria.